In my estimation, there has not been in American history a more important leak than Edward Snowden's release of NSA material – and that definitely includes the Pentagon Papers 40 years ago. Snowden's whistleblowing gives us the possibility to roll back a key part of what has amounted to an "executive coup" against the US constitution.

Since 9/11, there has been, at first secretly but increasingly openly, a revocation of the bill of rights for which this country fought over 200 years ago. In particular, the fourth and fifth amendments of the US constitution, which safeguard citizens from unwarranted intrusion by the government into their private lives, have been virtually suspended.

The government claims it has a court warrant under Fisa – but that unconstitutionally sweeping warrant is from a secret court, shielded from effective oversight, almost totally deferential to executive requests. As Russell Tice, a former National Security Agency analyst, put it: "It is a kangaroo court with a rubber stamp."

For the president then to say that there is judicial oversight is nonsense – as is the alleged oversight function of the intelligence committees in Congress. Not for the first time – as with issues of torture, kidnapping, detention, assassination by drones and death squads –they have shown themselves to be thoroughly co-opted by the agencies they supposedly monitor. They are also black holes for information that the public needs to know.

The fact that congressional leaders were "briefed" on this and went along with it, without any open debate, hearings, staff analysis, or any real chance for effective dissent, only shows how broken the system of checks and balances is in this country....